The Fearsome Nematodes of the Dry Valleys

Spectrum's Glenn Zorpette reports from Antarctica

Loading the podcast player...

This is part of the series:
Antarctica: Life on the Ice

Transcript: The Fearsome Nematodes of the Dry Valleys

Glenn Zorpette: The McMurdo Dry Valleys. The name suggests the wastelands of Australia. But it’s Antarctica, and it’s one of the most beautiful places I’ve ever seen. These Dry Valleys are among the most arid places on Earth. There’s very little snow, and not a lot of ice except for some scattered glaciers. And yet inside the Taylor Valley where I was standing…

[sound of water trickling]

Joseph Levy: When I came down into Taylor for the first time and heard that, it almost brought a tear to my eye. After two months of not hearing any liquid water except for what we have in the pot, and this is just—I love it.

Glenn Zorpette: Joseph Levy is a postdoctoral fellow with Portland State University and the McMurdo Long-Term Ecological Research group, also known as the LTER. Levy knew exactly where that noise of trickling water was coming from.

Joseph Levy: It’s the sound of some old ice. Water deposited 4000 years ago.

[sound of water trickling]

Glenn Zorpette: Up in the accumulation zone of one of the glaciers, apparently.

Joseph Levy: And right now, when the sun shines in the peak summer, it melts, flows down…into the streams, into the ponds, and ultimately into the lakes. So that’s what I’m interested in, the ground—it’s this big unexplored source for water, for chemistry, for all the things that the LTER is interested in.

Glenn Zorpette: These little trickles of water sluicing their way through the Dry Valleys can mean the difference between dormancy and animation to some rather well-adapted creatures.

Joseph Levy: The dominant predator here in the Dry Valleys is the fearsome nematode. It’s a microscopic worm that eats both algae and also other microbes.

Glenn Zorpette: Are there nematodes unique to this area?

Joseph Levy: The nematodes—most of them are endemic, so they’re from here and are unique to here. They adapt to the subfreezing temperatures in the winter by drying themselves out, and as soon as the first trickle of water comes from either melting snow in the spring or a trickle of water of a glacier, or in my interest, the melting of permafrost, the wicking up of water, they snap into activity and start eating, respirating, multiplying, and living their lives in the summer.

Glenn Zorpette: Nematodes belong to a simple food web to which Levy and his team are making small experimental tweaks. They add some extra water here, some extra food there, and observe how food webs respond to a changing environment.

Joseph Levy: And given that we’re part of the larger food web, seeing how the nematodes adapt tells us a little about how we adapt as a species.

Glenn Zorpette: Very few critters other than nematodes can live in the Dry Valleys. Take seals, for example. Ray Spain is a Raytheon employee who assists the scientists.

Ray Spain: We have a lot of mummified seals up and down the valley. We’re not really sure why they come up here. For some reason they tend to go further and further up valley, so they’re gaining altitude, and they’re going over big lumpy rocks. It can’t be easy travel, because they travel much better in water. And of course they die because they can’t get back to sea.

Glenn Zorpette: The seals will wander as far as 10, 12 miles away from the sea, hauling their blubbery bodies over rugged mountains and hills.

Ray Spain: Long way for a seal. With little tiny flippers for feet. And then there’s no bacteria here to break them down. So they just desiccate. They just dry out and become a bag of bones with beef jerky around them.

Glenn Zorpette: Goes to show just how hostile the Dry Valleys can be. Which is why Ray Spain takes the logistics and safety aspects of her job so seriously.

Ray Spain: We get people who arrive here who are graduate or undergraduate students who have never been camping before.

Glenn Zorpette: This is probably an unusual place to start camping, an arid Dry Valley in Antarctica.

Ray Spain: Yeah, but you know, if it’s the first time, you can just lay out the rules and say this is how you do it. Whereas if it’s somebody who’s camped a lot of other places, it’s probably harder, because they say, “What do you mean, I can’t just pee on the ground?” It might be harder that way. Most of the people—I’ve never had anybody come out here and just not been able to handle it.

Glenn Zorpette: What about challenges? Have you had any unusual challenges?

Ray Spain: Challenges. I would say personalities in a small space are the biggest challenge. We spend all our time together. You have one small building to share, and you’re with those people 24/7. You work with them, you eat with them, you’re just with them all the time. So you can imagine being stuck with your family in a small cabin. So even people you know very well, it can be very challenging after not just weeks but months.

Glenn Zorpette: Still, Joseph Levy finds the Antarctic, and the Dry Valleys in particular, an endlessly rewarding habitat to explore.

Joseph Levy: On those few occasions when the wind dies, and you’re 10 or 15 miles from camp, you’re the only soul in the valley, and it’s absolutely breathtaking. The opportunity, though, to really study this place, to understand it, to get an appreciation not just of its surface beauty but how it’s functioning and changing with time, is really the great opportunity. It is a life-changing experience, and it’s a very addictive place to do work. There’s a lot of data here, and a lot of information, and as you can hear, it’s critical because it’s melting out every day.

[sound of water trickling]